When the weather is cold, heaters are used in many public places or houses to improve room temperature. During the use of heaters, air is dried to cause discomfort. For this reason, humidifiers are used by many users while the heaters are turned on, so as to eliminate the problem of dry air via the humidifiers.
Recently, the addition of essential oil is desired by a part of users during the use of the humidifiers, so as to improve psychic state via fragrance generated by the essential oil. If the addition of essential oil in the humidifier is desired recently, however, it is only possible to drop essential oil into the atomization reaction zone without the water box being mounted to the humidifier such that essential oil is volatilized to generate fragrance while atomization reaction is performed in the humidifier. Nevertheless, the mass of essential oil is lower than that of water, such that the essential oil may float on water. In this way, the essential oil is volatilized rapidly, and thus the time period when mist contains fragrance may not meet expectations. Therefore, it is necessary for the user to disassemble and assemble the humidifier several times to keep mist containing fragrance continuously, which is truly inconvenient.